Are you human? Resistor edition

[PT] tipped us off about a new way to screen bots from automatically leaving comments. Resisty is like CAPTCHA but it requires you to decipher color bands on a resistor instead of mangled text. This won’t do much for the cause of digitizing books, but if you can never remember your color codes this is a good way to practice. Resisty comes as a plug-in for WordPress, add it to your blog and for a geek cred +1.

Very cute, but from the comments over there I gather the guy that made it is a bit of an ass.
But that should not matter really.
What does matter is that although cute it’s dead easy for the spambot makers to bypass this, so you’ll ruin your site in no time if you don’t watch it.

@B1rdm4n some common types of colorblindness don’t work well with standard monitors, various colors look the exact same, but there are ways to adjust the output of monitors to make it more distinct though.
Another problem is that a surprisingly large number of people that are colorblind are actually not aware of it (seriously), they were born with an understanding of color as being how they see it and don’t realize people with normal colorvision see it all different, just like we that can see colors normally have a hard time to imagine how colorblind people actually see things.

I’m surprised at how many colorblind electronic engineers there are here…

I mean…electronics…just about everything is color coded — talk about challenging yourself. This should be cake compared to the accidental grounding of electricity, mis-wired circuit boards, and of course recognizing your resistors…

@supershwa
Well an engineer can just enter the values in his computer, and when prototyping (after testing the circuit on the computer in emulation) get them from the right drawer, plus it’s all SMD now and they aren’t colorcoded bur have unreadable tiny text and are placed by robots.
And when confused you can measure the resistance with a simple meter too.

It doesn’t matter that the captcha is simple for a computer to crack, because the spammers have a willing army of thousands from Pakistan, China, and dozens of other 3rd-world countries to crack the “secure” ones…

Neat but you could just use autohotkey to compare the colorband to the colors available on the slider and click the ones that match. Might be more secure on geeky sites by just asking the resistance of the bands with no sliders.

at first i was thinking that this is cool, but incredibly easy to crack/hack, and worthless. after reading your comment it made me realize that if a large portion of sites made their own captchas, it would lessen the need drive to build captcha crackers programs. it probably would result in small sites receiving minimal to none spam.

From there we have to match the RGB codes to the form, the form values resist1,2,3,4 are set to match the number shown in the slider. These don’t change so we can swipe them once and get the 0-9 values.

Then we actually have to calculate the resistance and populate the hidden ohms and perc values using the code in the JS function getResistance().
resist = parseInt(resist1 + resist2) * Math.pow(10, resist3);

Now that we have resist1-4, ohms, and perc we can then fill in the standard WP form values and submit our post.

I wonder how it can be made better. Maybe using an actual product image of a resistor, so take a catalouge image of a 47K Ohm resistor and then show that to the user. Rotation of the image and varying the angle or width of the bands.

Its a neat and educational CAPTCHA. I had fun roughing out a script to get around it.

hiya, phil here – please read the post carefully. the goal is to teach people how to read resistors, that’s why we made it. we have many layers of spam protection on the site – if you take a look around adafruit you won’t see any spam comments in our very active blog (over 1m page views a month now) or the forums (thousands of posts a month). we have humans who read all the comments and posts carefully.

it’s not a CAPTCHA challenge, if that’s what you’re looking for – this isn’t for you :)

@phil – I saw CAPTCHA and immediately thought “anti-spam” and had to see if I could get around it. I certainly did not intend to show any disrespect to your work. It’s a great tool and it’s well coded, at least what I can see on the client side.

Another note, there are other free apps out there to teach resistors. With no dis-respect intended, I think simply associating this with CAPTCHA is whats bringing out all the negative comments. Yes it can be broke, and maybe thats just as fun for some as learning how to read a resistor for others. Either way, This project seams to have spawned two learning areas instead of one. I’d call it a win-win situation.

@jeicrash – i think the apps that teach resistors are for the people who are already interested – we’re thinking puzzles, science / engineering formulas and other topics that can be taught CAPTCHA-style might inspire people not only to post comments, but to learn something along the way.

there are people who just crack CAPTCHAs for a living, we’re not interested in them – and i know they’re not interested in our site. we review each comment, there’s no money to be made trying to spam our site, it’s a dead end for them.